空气资源评估方法及其在城市环境总体规划中的应用

从空气污染气候学的角度,提出了空气资源禀赋的概念、评估方法、等级划分及分区管控的理念.同时,以宜昌城市环境总体规划为例,利用MM5耦合CALMET模式对大气环境系统进行解析,计算了宜昌市域范围高时空分辨率(1 km×1 km)通风系数A值分布,并作为空气资源禀赋等级分区的依据.在此基础上,将空气资源分区的结果与地理信息系统相结合,给出其空间分布,强化了分区管控政策的空间落地.评估结果表明,宜昌地区空气资源禀赋等级共分为4级,A值在8以上的空气资源禀赋充裕的地区,约占市域面积的30.3%;较好和一般的地区,A值分别在5~8和3~5之间,约占34.1%和34.8%;A值在1~3之间空气资源禀赋稀少的地区,仅占0.8%.本研究提出的空气资源禀赋分区方法具有较强的合理性,预期在城市中长期发展过程中的产业布局与分级调控中具有较好的应用前景.     

MM5与CALMET对北京地区风能资源的初步模拟

利用MM5与CALMET模拟了北京地区10、30、50和70 m高度的风速和风功率密度分布,结果表明：各高度层风速与风功率密度的地域分布具有一致性,模拟的风速最大区位于门头沟西北部,而昌平西部、房山北部及延庆西部的风速次之,风速最小区位于顺义和东部城区;风功率密度的模拟显示京西地区和西北部地区的风资源较为丰富,北京东部、东南部和东北部及市区周边的风资源相对较小,开发潜力低。利用3座测风塔和3个气象站风速观测数据对模拟结果进行了初步检验,表明MM5与CALMET基本能模拟出风速的月变化和日变化特征,模拟和观测具有较好相关性,但模式存在对黄草梁和北梁地区模拟结果偏高、对涧沟地区模拟结果偏低的系统性误差,这可能与模拟区域地形复杂及模式自身分辨率不够等有关。     

全国空气资源评估及其与空气质量相关性分析

利用WRF耦合CALMET模式对大气环境系统进行解析,计算全国范围36 km×36 km分辨率通风扩散系数分布,作为空气资源禀赋评估的依据.评估结果表明,全国区域空气资源禀赋整体呈现东低西高,南低北高,内陆闭塞区低,沿海平原地区高的分布趋势.同时,存在三大空气资源禀赋优质区,一是位于河北与山西交界处的太行山脉和东北三省的长白山区域,二是位于西北部青海、新疆和西藏三省交界的昆仑山脉和唐古拉山脉区域,三是位于山东半岛、长三角和珠三角区域的沿海蓝色经济带区域.在此基础上,采用CALPUFF模型,结合观测数据,选取重点城市定量测算空气资源禀赋空间分布的差异性对城市空气质量的影响.以北京为参照,空气资源禀赋对成都、上海、青岛、郑州、广州等各城市群空气质量改善的相对影响程度分别为0.2%、13.2%、25.9%、29.1%和39.4%.     

SO2 modeling in İzmit Gulf, Turkey during the winter of 1997: 3 cases

In this study, SO₂ dispersion over İzmit Gulf is simulated by California Puff (CALPUFF) model for three air pollution cases, which occurred on January 28, February 12, and February 26, 1997. These days are generally characterized by dominant high-pressure systems – pressure values reaching 1032 mb, low wind speeds and sometimes calm conditions, and low temperatures with a minimum of 0°C. Hourly simulations during those critical cases were carried out and results revealed very high concentrations of SO₂ transported to the downwind regions of Tüpraş and Gebze, and values sometimes exceeded 1,000 μg/m³. Nighttime and morning simulations associated with inversion produced considerably higher values of SO₂ than the afternoon simulations associated with breeze. Model verification was conducted by comparing the measured daily average values of eight stations with the model predicted values at the same receptor points. Results showed that the model well predicted the values at station Gebze in all three cases. The model sometimes underestimated and sometimes overestimated the concentrations at other receptor stations.     

Analysis of meteorological parameters for dense gas dispersion using mesoscale models

The current study focuses on characterizing the atmospheric details required for dense gas dispersion analysis resulting from release of cryogenic liquids like LNG. The study investigates the effectiveness of coupling the prognostic MM5 mesoscale model with the CALMET diagnostic model for producing meteorological conditions that is characteristic of dry and arid regions like Qatar, with non-neutral boundary conditions. MM5-CALMET wind fields and temperature data are compared with the meteorological field observations from the Doha International Airport (DIA) on a monthly basis, daily basis and hourly basis to study the effect of different averaging periods. The monthly averages replicate the annual patterns of meteorological parameters very well. However difference in observation and model are observed for wind speed and wind direction variable. The daily averages obtained from the model are in good agreement with the observation for wind speed and temperature. For hourly averaging, the model is found capable of mimicking the temperature of a given location, but not wind speed and direction. The prediction of wind direction parameter using MM5-CALMET is moderate for any averaging period. The sub-optimal performance of wind direction variable is attributed to grid resolution of vertical and horizontal layers of MM5-CALMET model. Additionally a case study is performed to illustrate the effect of variation of meteorological parameters on the lower flammability limits (LFL) resulting from flammable dense gas release of LNG. The case study demonstrates the issues that arise in a risk analysis study when “wrong” meteorological data could be used. The overall study indicates that utilizing the coarsest prognostic meteorological model output in a diagnostic model provides an effective option for generating meteorological inputs for dispersion studies.     

湖北省风能资源的高分辨率数值模拟试验

利用边界层模式CALMET耦合中尺度模式MM5对湖北省的风能资源分布特征进行数值模拟,得到水平分辨率1 km、 垂直高度10~150 m覆盖全省的风能资源分布。通过与测风塔对比发现,模式对九宫山7月、 11月的逐时有效风速的模拟相关系数分别为0.59、 0.57;受下垫面复杂地形的影响,10 m高度上的误差最大,50 m高度的模拟效果好于其他高度。70 m高度上数值模拟风速年均误差为7.21%,逐月平均风速误差范围在6.62%~7.30%之间。全省风能资源的总体分布特征是:中东部大于西部,西部的等值线相对凌乱且密集,冬、 春季风速、 风功率大于秋季,西部地区为风资源较贫乏地区。数值模拟结果虽然存在一定的误差,但模拟得到的风能资源分布趋势是符合本地区气候和地形特征变化规律的,可以作为制定区域风电发展规划的科学依据。在进行风电场选址时,对于误差大于平均水平的地区需要多布设测风塔。     

大气扩散CALPUFF模型技术综述

介绍了CALPUFF模式系统的理论知识,以及在应用尺度、适用范围、气象与地形预处理、特殊计算功能模块等方面的特点和优势,综述了其模式验证及在国内的应用情况,提出了模型在应用方面的局限性。